Inhibitory effect of gonadotropin releasing hormone upon cultured testicular cells.
The direct inhibitory of gonadotropin-releasing hormone (GnRH) upon testicular androgen production was studied in cultured testicular cells. Enzyme-dispersed testicular cells from immature hypophysectomized rats were cultured for 6 days in a serum-free medium with or without various hormones. Culture media were changed every 2 days and media concentration of a androgens was measured by radioimmunoassay. The testis cultures from immature rats secrete predominately 5 alpha-androstane-3 alpha, 17 beta-diol (A-diol) and androsterone but negligible amounts of androstenedione, testosterone and dihydrotestosterone. Incubation of testicular cells with hCG and FSH increased A-diol and androsterone production as compared to control cultures. In contrast, treatment with GnRH or a GnRH agonist (des-Gly10, D-Leu6 (N alpha Me)Leu7, Pro9NHEt-GnRH) inhibited the gonadotropin effect in a dose-dependent manner; 10(-8) M GnRH inhibited A-diol production by approximately 20% on day 4 and 6 of culture whereas 10(-6) M GnRH inhibited A-diol production by greater than 80%. The observed effect of GnRH upon testicular cells in primary culture demonstrates that the hypothalamic peptide directly inhibits testicular steroidogenesis.
D000728:Androgens / Q000378:metabolism*; D015113:Androstane-3,17-diol / Q000378:metabolism; D000738:Androsterone / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D013196:Dihydrotestosterone / Q000378:metabolism; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D010906:Pituitary Hormone-Releasing Hormones / Q000494:pharmacology*; D051381:Rats; D013737:Testis / Q000187:drug effects / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism
D000728:Androgens; D006063:Chorionic Gonadotropin; D010906:Pituitary Hormone-Releasing Hormones; D013196:Dihydrotestosterone; D015113:Androstane-3,17-diol; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; C026680:LHRH, Leu(6)-Leu(N-alpha-Me)(7)-N-Et-ProNH2(9)-; D005640:Follicle Stimulating Hormone; D000738:Androsterone